1. Field of the Invention
The present invention relates to a radio communications method for communicating between a radio network controller which controls a location registration area which is formed by a plurality of cells and a mobile station located in the location registration area, and a radio network controller used in the radio communications method.
2. Description of the Related Art
In a radio communications system, network always needs to grasp location information of mobile stations which moves spatially, so as to automatically connect with the mobile stations.
Therefore, as shown in FIG. 1, the mobile station is configured to register the location information of the mobile station in the network in units of a location registration area which is formed by a plurality of cells.
To be more specific, when the mobile station detects that a location registration area where the mobile station is located changes (referring to a point “A” in FIG. 1), in accordance with a signal from a base station, the mobile station updates the location information registered in itself, and notifies the update to the network.
When power of the mobile station is turned on, the mobile station checks the location information registered in itself in accordance with the signal from the base station again. When the location registration area has changed where the mobile station is located, the mobile station registers new location information in the network.
However, there is a problem in that the conventional radio communications system does not have a means for measuring the number of the mobile stations capable of receiving broadcast data or multicast data, in a broadcast transmission system or a multicast transmission system which transmits same information to a plurality of mobile stations.